University of Cambridge researchers have achieved a breakthrough in organ transplantation by successfully converting the blood type of donor kidneys to the universal O type, a development that could dramatically expand transplant opportunities for patients on waiting lists. The team successfully altered three donor kidneys using an innovative enzyme-based technique that removes blood type markers from organ vessels.
Revolutionary Enzyme Treatment Process
The researchers utilized a normothermic perfusion machine, a device that passes oxygenated blood through kidneys to preserve them for transplantation, to deliver an enzyme treatment that strips away blood type markers lining the organ's blood vessels. This process effectively converts kidneys from type A or B to the universal O type, which can be transplanted into patients with any blood type.
"By taking B-type human kidneys and pumping the enzyme through the organ using our normothermic perfusion machine, we saw in a matter of just a few hours that we had converted a B-type kidney into an O type," said Serena MacMillan, a PhD student at the University of Cambridge who worked on the study.
The breakthrough emerged after initial testing on kidney tissue samples proved successful. "Our confidence was really boosted after we applied the enzyme to a piece of human kidney tissue and saw very quickly that the antigens were removed," MacMillan explained. "After this, we knew that the process is feasible, and we just had to scale up the project to apply the enzyme to full-size human kidneys."
Addressing Transplant Disparities
The development holds particular significance for minority ethnic communities, who face substantial barriers in finding compatible organ matches. Current transplant statistics reveal a stark disparity: while black and minority ethnic patients comprise 33% of the kidney transplant waiting list, only 9% of total organ donations in the UK come from these communities.
Professor Mike Nicholson, professor of transplant surgery at the University of Cambridge, highlighted the underlying challenge: "One of the biggest restrictions to who a donated kidney can be transplanted to is the fact that you have to be blood group compatible. Blood group classification is also determined via ethnicity and ethnic minority groups are more likely to have the rarer B type."
This blood type incompatibility means that people from minority ethnic groups often wait a year longer for a transplant than white patients. The ability to convert kidneys to universal type O could significantly reduce these waiting times and improve access to life-saving transplants.
Next Steps in Clinical Development
Before the technique can be implemented in clinical practice, researchers must conduct additional testing to ensure the converted kidneys function properly when exposed to different blood types. The team plans to use their perfusion machine system to introduce various blood types to the modified O-type kidneys and monitor their reactions.
"Now the researchers need to see how the newly changed O-type kidney will react to a patient's usual blood type in their normal blood supply," according to the research protocol. This testing phase will be crucial for determining the safety and efficacy of the converted organs before human trials begin.
The research, funded by charity Kidney Research UK, is scheduled for publication in the British Journal of Surgery in the coming months. Dr. Aisling McMahon, executive director of research at Kidney Research UK, described the work as "potentially game-changing."
Clinical Impact and Future Implications
The successful blood type conversion addresses a fundamental limitation in organ transplantation. Currently, a kidney from someone with blood type A cannot be transplanted to someone with blood type B, and vice versa, due to the body's natural production of antibodies against incompatible blood type markers.
"It's very exciting to think about how this could potentially impact so many lives," MacMillan noted, emphasizing the broad therapeutic potential of the technique.
The research represents a significant step toward expanding the donor pool and reducing transplant waiting times, particularly for underserved populations who face the greatest challenges in finding compatible organs. If clinical trials prove successful, this enzyme-based conversion technique could transform organ allocation and improve transplant outcomes across diverse patient populations.
